I am looking for a solution to stream data from Oracle 11g to Kafka. I was hoping to use GoldenGate, but that only seems to be available for Oracle 12c. Is the Confluent platform the best way to go?
Thanks!
First, the general answer would be: The best way to connect Oracle (databases) to Kafka is indeed to use Confluent Platform with Kafka's Connect API in combination with a ready-to-use connector for GoldenGate. See the GoldenGate/Oracle entry in section "Certified Connectors" at https://www.confluent.io/product/connectors/. The listed Kafka connector for GoldenGate is maintained by Oracle.
Is the Confluent platform the best way to go?
Hence, in general, the answer to the above question is: "Yes, it is."
However, as you pointed out for your specific question about Oracle versions, Oracle unfortunately has the following information in the README of their GoldenGate connector:
Supported Versions
The Oracle GoldenGate Kafka Connect Handler/Formatter is coded and
tested with the following product versions.
Oracle GoldenGate for Big Data 12.2.0.1.1
Confluent IO Kafka/Kafka Connect 0.9.0.1-cp1
Porting may be required for Oracle GoldenGate Kafka Connect
Handler/Formatter to work with other versions of Oracle GoldenGate for
Big Data and/or Confluent IO Kafka/Kafka Connect
This means that the connector does not work with Oracle 11g, at least as far as I can tell.
Sorry if that doesn't answer your specific question. At least I wanted to give you some feedback on the general approach. If I do come across a more specific answer, I'll update this text.
Update Mar 15, 2017: The best option you have at the moment is to use the Confluent's JDBC connector. That connector can't give you quite the same feature set as Oracle's native GoldenGate connector though.
Oracle GoldenGate and Confluent Platform are not comparable.
Confluent Platform provides the complete streaming platform and is a collection of multiple software which can be used for streaming your data, where as GoldenGate is replication and data-integration software.
Also GoldenGate is highly reliable for db replication since it maintains transactional integrity, same cannot be said for Kafka Mirror Maker or Confluent's Replicator at this time.
If you want just pure transactions - please also consider using OpenLogReplicator. It supports Oracle database from version 11.2.0.1.
It can produce transactions to Kafka in 2 formats:
Classic format - when every transaction is one Kafka message (multiple DMLS per Kafka message)
Debezium style format - transactions are divided - every DML is one Kafka message
There is already a working version. You can try it.
Right now I am using ojdbc6 to connect to Oracle 11g. It is good enough but not perfect especially when using pooling mode to check if there are new updates on the original tables.
I tried also to read all tables using certain pattern but this did not work well.
The best mode to connect an Oracle DB to Kafka (especially when the tables are very wide, columns wise, is to use queries for the connectors. This way, you ensure that you pick the right fields and do some casting for numbers if you are using avro.
Related
In the documentation of OrientDB it mentioned that encryption at rest is not supported on remote protocol yet. It can be used only with plocal.
Currently we are using the OrientDB version 2.2.22. Database encryption is mandatory for us. We were previously using OrientDB in plocal mode, but now we have a new requirement in which multiple processes from different JVMs need to connect with same OrientDB database, which is not possible in plocal model.
Is there any way we can achieve it? Is there any workaround? Is this feature going to be supported in upcoming releases?
If you start your server and provide the key at startup, from that point on, the database is accessible via remote. So it would work. I suggest encrypting the TCP/IP connection too at that point.
No, it cannot currently be done:
NOTE: Encryption at rest is not supported on remote protocol yet. It can be used only with plocal.
Given your new requirements, it seems like OrientDB is not the right choice for you anymore.
Is it possible to use single table for multiple connections in cassandra?
I am using a spring data for java connection and am trying to use python flask for raspberry connection.
Yes, you can use single tale for multiple connections. I'm using Cassandra 2.2 where I connect using Java Astyanax driver and python pycassa client.
Are you referring about table lock for transactions? Cassandra does not use any locking mechanism on data, the below docs link describes more on transactions and consistency in Cassandra:
http://docs.datastax.com/en/archived/cassandra/2.0/cassandra/dml/dml_about_transactions_c.html
Mention what you tried and problems you faced.
If we have 500 processes accessing SQLite, is it possible to host it as a separate process, so all 500 processes do not have to perform IO.
These processes can attach to one instance of SQLite and access data. Is it possible twith SQLite
The short answer is no. SQLite isn't a client/server database, it's just code linked into your application/process. There are 3rd party client/server implementations of SQLite, but I've never used one and can't speak to their quality. It sounds like you may be better off looking at client/server dbs such as PostgreSQL or MySQL.
It might also be worth reading Appropriate Uses For SQLite to see if your particular use case is a good fit for SQLite or not.
I'm developing an application that works distributed, and I have a SQLite database that must be shared between distributed servers.
If I'm in serverA, and change sqlite row, this change must be in the other servers instantly, but if a server were offline and then it came online, it must update all info equal other servers.
I'm trying to develop a HA service with small SQLite databases.
I'm thinking on something like MongoDB or ReThinkDB, due to replication works fine and I have got data independently server online I had.
There are a library or other SQL methodology to share data between servers?
I used the Raft consensus protocol to replicate my SQLite database. You can find the system here:
https://github.com/rqlite/rqlite
Here are some options:
LiteReplica:
It supports master-slave replication for SQLite3 databases using a single master (writable node) and one or many replicas (read-only nodes).
If a device went offline and then it came online, the secondary/slave dbs are updated with the primary/master one incrementally.
LiteSync:
It implements multi-master replication so we can write to the db in any node, even when the device is off-line.
On both we open the database using a modified URI, like this:
“file:/path/to/app.db?replica=master&bind=tcp://0.0.0.0:4444”
AergoLite:
Blockchain based, it has the highest level of security. Stores immutable relational data, secured by a distributed consensus with low resource usage.
Disclosure: I am the author of these solutions
You can synchronize SQLite databases by embedding SymmetricDS in your application. It supports occasionally connected clients, so it will capture changes and sync them when a server comes online. It supports several different database platforms and can be used as a library or as a standalone service.
You can also use CopyCat, which support SQLite as well as a few other database types.
Marmot looks good:
https://github.com/maxpert/marmot
From their docs:
What & Why?
Marmot is a distributed SQLite replicator with leaderless, and eventual consistency. It allows you to build a robust replication between your nodes by building on top of fault-tolerant NATS Jetstream. This means if you are running a read heavy website based on SQLite, you should be easily able to scale it out by adding more SQLite replicated nodes. SQLite is probably the most ubiquitous DB that exists almost everywhere, Marmot aims to make it even more ubiquitous for server side applications by building a replication layer on top.
hoping someone has experience with both sql server and postgresql.
Between the two db's, which one is easier to scale?
Is creating a read only db that mirrors the main db easier/harder than sql server?
Seeing as sql server can get $$, I really want to look into postgresql.
Also, are the db access libraries written well for an asp.net application?
(please no comments on: do you need the scale, worry about scaling later, and don't optimize until you have scaling issues...I just want to learn from a theoretical standpoint thanks!)
Currently, setting up a read-only replica is probably easier with SQL Server. There's a lot of work going on to get hot standby and streaming replication part of the next release, though.
Regarding scaling, people are using PostgreSQL with massive databases. Skype uses PostgreSQL, and Yahoo has something based on PostgreSQL with several petabyte in it.
I've used Postgresql with C# and ASP.Net 2.0 and used the db provider from devart:
http://www.devart.com/dotconnect/postgresql/
The visual designer has a few teething difficulties but the connectivity was fine.
I have only used SQL Server and not much PostgreSQL, so I can only answer for SQL Server.
When scaling out SQL Server you have a couple of options. You can use peer to peer replication between databases, or you can have secondary read-only DB(s) as you mention. The last option is relatively straight-forward to set up using database mirroring or log shipping. Database mirroring also gives you the benefit of automatic switchover on primary DB failure. For an overview, look here:
http://www.microsoft.com/sql/howtobuy/passive-server-failover-support.mspx
http://technet.microsoft.com/en-us/library/cc917680.aspx
http://blogs.technet.com/josebda/archive/2009/04/02/sql-server-2008-database-mirroring.aspx
As for licensing, you only need a license for the standby server if it is actively used for serving queries - you do not need one for a pure standby server.
If you are serious, you can set up a failover cluster with a SAN for storage, but that is not really a load balancing setup in itself.
Here are some links on the general scale up/out topic:
http://www.microsoft.com/sqlserver/2008/en/us/wp-sql-2008-performance-scale.aspx
http://msdn.microsoft.com/en-us/library/aa479364.aspx
ASP.NET Libraries are obviously very well written for SQL Server, but I would believe there exists good alternatives for PostgreSQL as well.